Two groups of drugs which are heavily used by the elderly have been subjected to molecular manipulations in order to learn how their pharmacological profiles can be improved. In the group of beta-adrenergic blockers it has been established that introduction of chemically reactive moieties into drugs may have considerable therapeutic potential. The chemical reaction between such a drug and its receptor in tissue was found to make the effects of the drug longer lasting in maturing rats; in senescent rats the effects were prolonged dramatically and were noticeable even one month after the drug was applied. These findings point to the possibility of developing drugs which would have to be applied only a few times during senescence. In the field of fat soluble vitamins new potent solubilizing agents were developed which may decrease toxic effects of "megavitamin" treatments.